Method for restoring pressure in tennis balls



Aug, 27, 193% G. MILLER gamlzvzgg METHOD FOR RESTORING PRESSURE INTENNIS BALLS Original Filed Sept.-4, 1929 GUSTAVE MILLER.

[NVENTQR cH-euwkk ATTORNEY Patented Aug. 27, 1935 7UNITED STATES PATENTOFFICE METHOD roe RESTORING PRESSURE IN TENNIS BALLS Gustave Miller, NewHaven, Conn.

Original application September 4, 1929, Serial No.

Divided. and this application January (Granted under the act of, March3, 1883, as amended April 30, 1928; 370 O. G. 757) This inventionrelates to a method and means for restoring and retaining a desiredpressure in tennis/balls and the like, and is a division of anapplication filed September 4th, 1929, Serial No. 390,317, and patentedMay 23, 1933 No. 1,911,125 for Pressure ball container.

As is well known, tennis balls-are elastic because they have air or gasunder pressure therein, and to be acceptable, a tennis ball must have adesired amount of bounce or rebound when dropped a predetermineddistance on a hard surface. This distance is regulated by the tennisassociation, and balls which do not comply with such conditions are notallowed in play. As sold when fresh, balls are usually in the propercondition, and there have recently appeared on the market balls soldeither in cans or covers wherebythe balls are protected against losingthe pressure therein by being sealed in a can or container having apressureequal to the pressure in the balls. This serves to keep theballs fresh until the can or container is opened, and the can orcontainer being then destroyed by theact of opening, is thrown away.Thereafter, the ball begins to lose its life and to go dead through thepressure escaping-either as a result of being hit by the rackets in playor by being exposed to the atmosphere.

.This invention has for an object to reliven dead balls as well as tokeep the balls fresh while they are in the possession of the playerafter he has removed them from the original container, and to restorethe pressure in the balls that may escape during'play. I

A further object of this invention isto provide akmethod whereby theplayer may restore the balls to their original freshness, after theyhave been played with, and to. provide a method of keeping them freshindefinitely until he is again ready to use them in play.

is shown at In a container or can of a size to contain a plurality oftennis balls H, preferably three balls being placed therein. This can isclosed by a cover 12 and has a valve l3 to admit pressure therein. Thecover l2 has a flange H which is internally threaded as at 15, while themouth 15 of the can In is externally correspondingly threaded at ll. Thecan and cover may be of any suitable metal or alloy as will not allowpressure to readily escape therethrough, and will preferably be of aslight a metal as possible, to m reduce the weight of the completearticle. The threads will be machined therein so as to fit each other asnearly as possible. The cover flange M will have asealing material l8placed therein as shown, which will partially cover the threads tightclosure therefor. Due to the excess threads 35 and sealing materialpresent as shown, it is obvious that the cover may be removed andreplaced an indefinite number of times, and that new sealing material 16may be added when that present is finally worn away. The outside of thecover-flange as well as the outside of the can nearthe bottom may beknurled as at 20 so as to give a better grip to the hands when openingor closing the can 10.

The valve l3 provides for the admission and u regulation of the pressurein the can and may be attached through an opening in the can, either inthe bottom or in the cover, and is here shown as being through anopening 22 which may be threaded as shown if desired, to correspond to athreads 23 on the outside of the valve body 13. Valve body 13 has aprojecting flange 24, While a retaining'nut 25 may be screwedabout thevalve body inside the can or cover to hold it in place,

there being either or both washers 26 above or below the cover so as tomake a pressure tight closure, washers 26 being ofrubber or soft sealingmetal, as lead or the like.

Projecting through valve body I3 is an opening opening 21 will be screwthreaded at 29 to correspond with the standard thread of an internalmale pump, such as the small bicycle pumps in ordinary use, and athreadedprojecting flange 30 '21 which is enlarged at the inner end asat 28. The

may surround this opening so that a female threaded pump may be used ifdesired, or this flange may be connected to the air pumps in use at mostgasoline stations. As is obvious, this threaded flange can be omitted ifdesired, and then onlyan' internal male pump can be used. In theenlarged opening 28, aball valve 32 is held by a spring 33 against abeveled ball seat 24 formed at the inner end of the opening 21. The ballspring 33 will be held in place by a threaded plug 35 which is screwedinto opening 28, there being a spring retaining shoulder 35 recessedinto the plug. An opening 3'! through the plug 35 admits the air intothe can, and plug 35 has a slot 38 whereby a screw driver'may' be usedto ,as-

semble it.

Another threaded opening 39 identified in size with opening 28 is formedon the outside of the valve body 13, and a ball valve 40 is held thereinagainst a ball seat 4| formed against a small interior opening 42. Thisopening 42 is connected with opening 2! through a by pass 43 which isdrilled into the side of the valve body I3 through openings 42 and 2'!and then has its end permanently sealed by asolder plug 44 or the like.The ball ,valve 43 is held in place by a valve spring 45 which is seatedagainst a recessedshoulder 46 in athreaded plug 41 screwed into theopening 39. Thisplug 41 is identical with plug 35, and has a similaropening 48 to allow air to pass therethrough and has a screw driver slot49 for adjusting thetension of the spring 45.

. ,This plug 41 may have graduations on its outer end. as at 53 to coactwith a zero mark 5| on the valve body to assist in adjusting thepressure exerted by spring 45. A flange 52 projecting from ,thevalvebody is threaded at 53 to receive a dust jcap 54 there being a washer 55placed inside the dust cap. The cap may be also knurled as at 56 toassist in removing and replacing the cap.-

In operation, the tennis balls usually two or three in" number, will beplaced in the can at the end, of the day's play. The cover I2 is thenplaced landscrewed down until it is tight, the tapered ed e of the mouthpressing into the sealing material l 8.. The dust cap 54 is then removedand a pump applied to the'pressure opening 27. A small bicycle pump (notshown) may be used, and may be kept in-a special pocket in the tennisracket cover, and the can It! may also be kept in a pocket in the tennisracket cover as the balls were formerly kept. When the air is pumpedinto the ppening, it will force its way past the ball 32 and throughopenings 36 and 28 into the can. The ball valve 40 acts as a pressureregulator, being held in place by the spring 45. The tension of thespring45 may be adjusted by turning the plug 41, the graduations 55 andzero 5! assisting in setting ,the tension. Ordinarily the tension ofball valve 40 will be so set as to yield when the pressure in the can isjust slightly more than the pressure in a fresh or live tennis ball.Then, any additional pressure will not pass pressure valve 32, but willgo through the by pass 43 to escape past the regulating valve 40 throughopening 48 to the outside of the can, and the sound of this escaping airwill warn the user that the desired pressure in the can has beenreached. If the balls have been played with very hard, or have been leftout of the can forquite a while, the pressure in such balls is apt to bemuch less than that desired. In .such a case the plug 4'! maybe turnedso as to in- ;crease the pressure of spring 45 against ball 40, wherebyan increased pressure will result in the 1 can when pumped, before theregulating valve will open. The balls will thus be kept in a pressuregreater than that already in the balls, and this excess pressure willleak into the balls to restore them to the desired pressure in the samemanner that the pressure in the balls leak out to the atmosphere todeaden the balls when they are kept without the protection of thispressure container. When the desired pressure is reached,

the dust cap 54 may be replaced and this will assist in preventing any.escape of pressure through the valve mechanism.

To use the balls again, the cover is removed by unscrewing it. Shouldthe pressure make it difiicult to turn the cover in spite of the knurled.portion in the cover'and can, the pressure may be released by merelypressing a slender object such as a match stick or dull nail throughopena ing 2'! against ball 32, and the cover will then be more easilyremovable.

Should the pressure in the balls be very low, or should it be necessaryor desirable to restore the pressure more rapidly, the regulating valvemay be so adjusted to admit a much greater pressure into the can thannormal, and allow it to remain in the can for a limited period of timeuntil the ball has reached the proper pressure, and then the pressure isrelieved and by readjusting the regulating valve, restored to the properdegree. Or, instead of the player owning such a container himself, theground keeper at the tennis courts could keep such a can, and for anominal fee could subject a players dead balls to a very excessivepressure for a short time to quickly restore them to live or playingcondition before the balls are played with. Tables of figures would befurnished the ground keeper, which would set forth the amount ofpressure and period of time a ball should be kept therein to quicklyrestore the pressure. The condition of the ball. may be determined byallowing it to drop from a standard distance. and measuring its bounce;a ball that lacks 5 inches of bounce being subjected to less pressure,or less time, than a ball lacking 10 inches of the desired amount ofbounce. The ground keeper can easily determine the amount of bouncenecessary by dropping the ball onto a cement sidewalk alongside ayardstick or similar measured stick and watching the height to which itbounces, and with the figure determined by the bounce the tableswillinform the ground keeper how much pressure and time is necessarytorestore the ball to live condition. Obviously, when used by a groundkeeper at a tennis court, a much larger container holding a greatplurality of balls would be used, which container is not limited to theparticular one disclosed except withinthe limit of what is hereinafterclaimed.

Thus, it willbe apparent that this invention provides a methodpreserving and restoring the desired pressure in tennis balls or thelike, to keep the balls alive for an indefinite period of time, sothatone set of balls may last a complete season, or even several seasons,and still remain as ,to a higher gas pressure thanthat in saidball. 2. Amethod, of restoring a desired internal gas pressure in tennis balls andthe like, comprising subjecting the ball to a gas pressure higher thanthe desired pressure, and allowing the ball to remain under such higherpressure until the pressure in said ball reaches the desired pressure.

3. A method of restoring and retaining the desired internal gas pressurein tennis balls and the like, comprising subjecting the ball to a highergas pressure until the pressure in the ball reaches the desiredpressure, and then subjecting the ball to a gas pressure equal to thedesired pressure to retain the desired pressure.

4. A method of restoring the gas pressure within dead tennis balls,comprising subjecting the entire external surface of dead ball to apredetermined gas pressure in-excess of the desired pressure for alimited period of time.

5. A method of restoring gas pressure to the cavity within a tennis ballrendered less useful or dead by loss of internal pressure due to use orage, comprising exposing the external surface of such used ball to ahigher gas pressure than that within the same until such higher pressurehas penetrated through the imperforate wall of the ball.

6. A method, practicable with a readily openable and closablereceptacle, of restoring a desired gas pressure within a tennis ballrendered less useful by loss of internal pressure due to use or age,comprising subjecting the exterior surface of the used ball to a gaspressure within the receptacle higher than the desired gas pressure,allowing such used ball to remain in such high pressure until the highpressure penetrates the imperforate wall of said ball and causes theinterior pressure in said ball to reach the desired pressure and thenremoving the ball from said receptacle and pressure for re-use.

7. A method, practicable with a readily openable and closablereceptacle, of restoring and retaining the desired gas pressure withinthe cavity of a closed container chiefly useful outside said receptacle,comprising placing the container in the receptacle, subjecting theexterior surface of the container to a higher gas pressure within thereceptacle for such a limited period of time that the gas pressurewithin the container reaches the desired gas pressure, then subjectingthe container to a gas pressure within the receptacle equal to thedesired gas pressure to retain said desired gas pressure in thecontainer, and finally removing the restored container from thereceptacle for re-use.

8. A method, practicable with a readily openable and closablereceptacle, of restoring and retaining the desired gas pressure in thecavity of a tennis ball having less than the desired gas pressure,comprising placing the tennis ball within the receptacle, passing anexternally generated gas pressure through a readily openable andclosable opening into the receptacle sufliciently high to compensate forthe lower-thandesired gas pressure within the tennis ball and passingsome of the receptacle contained gas pressure through the wall of theball until the gas pressure in the receptacle and the gas pressure inthe tennis ball cavity will equalize to the desired gas pressure withinthe ball, retaining the ball with said desired gas pressure within thereceptacle until ready for use and then removing the gas pressure andball from the receptacle.

GUSTAVE MILLER.

